title: Per-N-methylated analogues of an antitumor bicyclic hexapeptide RA-VII.
abstract: Penta-N-methyl and hexa-N-methyl analogues of RA-VII, an antitumor bicyclic hexapeptide of plant origin, were prepared. In the former, the nitrogens of d-Ala-1 and Ala-4 and in the latter, those of d-Ala-1, Ala-2, and Ala-4 were methylated under the phase-transfer catalysis conditions. Their solution structures were established by NOESY experiments and the crystal structures by X-ray crystallography. Those two methylated analogues showed much weaker cytotoxicity against P-388 leukemia cells than the parent RA-VII.
authors.affiliation: School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hitotsuyanagi
authors.forename: Ji-Ean
authors.initials: JE
authors.lastname: Lee
authors.forename: Saori
authors.initials: S
authors.lastname: Kato
authors.forename: Ik-Hwi
authors.initials: IH
authors.lastname: Kim
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kohashi
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Fukaya
authors.forename: Koichi
authors.initials: K
authors.lastname: Takeya
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology; D018360:Crystallography, X-Ray; D006801:Humans; D007941:Leukemia P388 / Q000188:drug therapy; D051379:Mice; D008968:Molecular Conformation; D009842:Oligopeptides / Q000737:chemistry* / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000494:pharmacology*; D045470:Rubia / Q000737:chemistry
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D009842:Oligopeptides; D010456:Peptides, Cyclic; C043548:RA VII